Managing Your Managing Your Hard Disk and Hard Disk and

Operating SystemOperating System

23,26 March 2004

2:30pm - 4:00pm

Knowing yourHard Disk and Partition

Management

Multiple Operating System

Physical Geometry About Your Disk

Side(Head) Cylinder (Tracks per Side) Track Sectors/Track Cluster

1 Sector = 512 Bytes Capacity = Cylinder x Head x Sector x 512 Bytes e.g. A hard disk with 1023 Cylinders, 6 Heads and 63 Sectors/Track (CHS=1023/6/63)

– Capacity = 1023 x 6 x 63 x 512 Bytes = 386694 sectors = 197987328 B = 188.8 MB

Side/Head

Track

Sector

Limitations of Your System

Hard disk BIOS/ Partition Table

Min. Val.*

Max. Sectors 255 63 63

Max. Heads 16 255 16

Max. Cylinders

65536 1024 1024

Max. Cap. 136 GB 8.4 GB 504 MB

* The disk capacity limited by the min. values.

To Overcome the Limitations

Address Translation– Controller board on hard disk translates the the CHS

values such that the no. will not exceed the max. no. allowed in BIOS and partition table.

– Convert the physical values to logical values, e.g. 2000/16/631000/32/63

Modify BIOS’s design– For addressing still using traditional CHS values

Logical Block Addressing (LBA)– LINEAR addressing instead of using CHS values

Newer OS/file system e.g. FAT32, NTFS

Logical Block Addressing (LBA)

Suppose a Hard disk with CHS=2040/16/63 To access a sector on Cyl:2000, Head:10, Sect:60

(CHS=2000/10/60) LBA value = 2000 x 16 x 63 + 10 x 63 + 60

= 2016690Sect 1 Sect 63

Head 0 Head 1

Sect 126

Head 15

Sect 1008

Cyl. 0

Sect 2016690

C=2000H=10S=60

Limitation of Logical Block Addressing (LBA)

Hard disk BIOS/P.T. LBA mode

Max. Sectors 255 63 63

Max. Heads 16 255 255

Max. Cylinders

65536 1024 65536

Max. Cap. 136 GB 8.4 GB 502GB

* Most hard disk use 28-bit LBA addressing. Max. Capacity of 28-bit LBA = 228Sectors = 128GB

* Newest hard disk use 48-bit ~ 1 Million times bigger!

File Systems

Popular file systems for PCs

File Allocation Table (FAT)– FAT12, FAT16, FAT32– DOS, Win9x/Me/NT/2000/XP

High Performance File Sys.(HPFS)– IBM’s OS/2

New Technology File Sys.(NTFS)– Win NT/2000/XP

EXT 2,3– Linux

Type of FAT system

FAT12– 12bits cluster addressing # of cluster = 212 = 4K– 1 cluster = 1 sector = 512 Bytes– Max. capacity = 2 MB– Mainly for floppy disk

FAT16– 16bits cluster addressing # of cluster = 216 = 64K– 1 cluster = 4~64 sectors = 2KB~32KB– capacity = 128 MB ~ 2 GB– Mainly for DOS

FAT32– 32bits cluster addressing # of cluster = 232 = 4G– 1 cluster = 8~64 sectors = 4KB~32KB– capacity = 512 MB ~ 2 TB– Mainly for Win 9X

File Allocation Table (FAT) file system

Boot Sector

FAT (store usage of clusters)

Root Directory

User data area (addressable by cluster #)

Disk Space

Clusters #

Partitions

Why Partition?

Organize and protect important data– e.g. OS in C:, Data in D:

Run several operating system with one HD Gain access to large disk (for FAT16 or older

file systems) Minimize wasted disk space

– Larger disk Larger Cluster size

more wastage of space– smaller partition smaller Cluster size less wastage

Partition Table

located in Master Boot Record (MBR) Storing information of partitions Max. 4 partitions in a table Can be Extended

Disk Space addressable by Sector#

MBR/Partition Table Partitions

Win Xp Win 98 Data

Primary and Extended partitions

MBR

Extended

Win XP

Win 98

MSDOS

Partition Table

F:

Extended

E:

D:

ExtendedPartition Table

Primary Partitions

Extended Partitions

Logical drives

Linux swap

Linux

ExtendedPartition Table

Boot Code

A Typical Partition Table

System

Type Boot

Start End Relative

Sect.

No. of

Sect.Side Cyl. Sect. Side Cyl. Sect.

6 80 1 0 1 254 63 63 63 1028097

7 00 0 64 1 254 324 63 1028160 4192965

5 00 0 325 1 254 970 63 5221125 10377990

b 00 0 971 1 254 1023 63 15599115 4192965

Some Typical System Type:5 Extended Partition6 DOS FAT-167 HPFS/NTFSb FAT-32c FAT-32X(Cyl > 1024)

Screenshot of DISKEDIT

Screenshot of SPFDISK

Partition Management

Create Delete Re-size Move File system conversion Hide/Unhide

Tools for partition management

FDISK (MSDOS, Win 9X, Linux) Partition Magic System Commander Norton GHOST Many of freeware/shareware from Internet

e.g. SPFDISK, EFDISK

Why not just use FDISK?

Can create only one primary partition– multiple primary partition needed for multiple OS

Destroy data in partition after creation or deletion

Cannot change system ID (type) which is helpful in preparing multiple boot system

Cannot hide partition

Comparison among Some Tools

FDISK

Partition Magic

System Commander

SPFDISK

Create / Delete

Resize / Move

×

Change Sys. Type

×/ × ×

Hide / Unhide

×

Edit Partition Table

×/ × ×

Installing Multiple Operating System

Why use multiple OS?

Better utilization of large hard disk Allows OS with

– different capability» e.g. WinXP for working, Linux for testing …

– different user» e.g. One for me, one for brother,…

– different purpose» e.g. One for software download, one for internet-ban

king

* Be sure you are properly LICENSED!

Ways to run Multiple OS

Hard Disk Partitioning Running Virtual Machine in Host OS

– VMware (for Win NT/2000/XP)– Virtual PC (for MAC)

Create Multi-boot System by Partitioning

Perform system check to make sure no disk error

Re-size your current partition to free up space for other OS

Create and format another primary partition Install a Boot Manager Install another Operating System Be careful if the OS will destroy the MBR

How Is Your Computer Boot Up

Single OS System

Power on

BIOSPOST

Floppy

CD-ROM

HD 0

HD 1

Load MBR On HD 1st Pri. Partition

Boot sequence

How Boot Manager Works

Multiple OS System

Power on

BIOSPOST

Floppy

CD-ROM

HD 0

HD 1

Load MBR On HD

Boot Manager Win XP

Win 98

Linux

Boot sequence

Some Boot Managers

System Commander Reborn Card Boot Manager Plus (BMP) Smart Boot Manager (SMB) SPFDISK Build in OS

– e.g. Win NT/2000/XP, Linux, OS/2 Many many from Internet

Something to Consider

File system type ?– FAT16, FAT32 or NTFS ?

Partition location– Some OS cannot boot beyond 2GB

boundary(Cyl.>1023)– e.g. Win NT/2000, Linux (older ver.)

Try it yourself!

Try the following steps:

Delete partition using FDISK Use SPFDISK to create partitions Use GHOST to restore partitions Install a Boot-manager Configure the Boot Manager Done!

The End

Thank You!